From DE 10 2007 000 561 A1, a transmission device with a hydraulic system is known; the transmission device includes a primary pressure circuit and a secondary pressure circuit. The secondary pressure circuit can be supplied with hydraulic fluid from a defined saturation condition of the primary pressure circuit. In addition, the transmission device is designed with a hydrodynamic torque converter formed with a “three-line converter” and a converter lock-up clutch corresponding to the hydrodynamic torque converter. The converter lock-up clutch is actuated through the primary pressure circuit with an operating pressure that is adjustable in the area of the converter clutch valve. In the open operating state of the converter lock-up clutch, an inner torus chamber of the three-line converter is subjected to a converter pressure that is adjustable in the area of the converter pressure valve through a converter switching valve of the secondary pressure circuit. The operating pressure of the converter lock-up clutch applies in the closing direction, and the converter pressure in the inner torus chamber of the three-line converter applies in the opening direction of the converter lock-up clutch acting on the converter lock-up clutch.
In the control state and in the fully closed operating state of the converter lock-up clutch, the inner torus chamber of the three-line converter, starting from an area of the hydraulic system guided by an operating pressure of the converter lock-up clutch area, is subjected to hydraulic fluid. However, disadvantageously, during unsaturated operating states of the primary pressure circuit of the hydraulic system, this leads to the fact that function groups of the transmission device to be provided with hydraulic fluid by the primary pressure circuit, that is, in addition to the converter lock-up clutch and additional transmission components, such as switching elements and the like, including a cooling device of the three-line converter in a normal operating state and in a closed operating state of the converter lock-up clutch, are not subjected to hydraulic fluid in the necessary extent under certain circumstances.
In addition, actuator dynamics of the transmission device are impaired by the additional supply of the three-line converter through the primary pressure circuit with the converter lock-up clutch subjected to operating pressure. The volume flow of hydraulic fluid removed from the primary pressure circuit in the direction of the three-line converter can be compensated for by increasing, for example, a volume flow of hydraulic fluid made available through a main transmission pump; however, the additional supply of the hydraulic system of the transmission device takes place through the main transmission pump in a delayed extent, which impairs the desired high dynamics of a transmission device.